1. Technical Field
The present invention relates to apparatus for sealing a fluid chamber, and particularly to apparatus for sealing a fluid chamber of a fluid power rack and pinion vehicle steering gear.
2. Description of the Prior Art
A fluid power rack and pinion vehicle steering gear commonly includes a rack which extends axially through a chamber. The ends of the rack project axially outwardly from the ends of the chamber. Steering linkage is connected to the projecting ends of the rack and to steerable wheels of the vehicle.
A piston is fixed to the rack within the chamber. Rotation of the vehicle steering wheel actuates a hydraulic valve and causes fluid under pressure to be directed against the piston. The force exerted by the fluid moves the piston within the chamber and moves the rack axially. Axial movement of the rack moves the steering linkage to turn the steerable wheels of the vehicle.
To prevent fluid from flowing out of the chamber, it is necessary to seal the ends of the chamber through which the rack projects. It is also desirable to support the rack at least at one end of the chamber for axial movement. Accordingly, various combinations of seals and bushings have been employed for performing these functions.